The present invention relates to an inhibitor of MEK and/or ERK activity useful for the treatment a variety of cancerous and non-cancerous disorders, including brain, lung, squamous cell, bladder, gastric, pancreatic, breast, head, neck, renal, kidney, ovarian, prostate, colorectal, colon, epidermoid, esophageal, testicular, gynecological or thyroid cancer; restenosis; benign prostatic hypertrophy (BPH)); pancreatitis; kidney disease; pain; vasculogenesis or angiogenesis (e.g., tumor angiogenesis); acute and chronic inflammatory disease such as rheumatoid arthritis, atherosclerosis, inflammatory bowel disease; skin diseases such as psoriasis, eczema, and scleroderma; diabetes; diabetic retinopathy; retinopathy of prematurity; age-related macular degeneration; asthma; neutrophil chemotaxis; septic shock; multiple sclerosis; chronic obstructive pulmonary disease; and others. Specifically the present invention relates to (R)-3-(2,3-dihydroxypropyl)-6-fluoro-5-(2-fluoro-4-iodophenylamino)-8-methylpyrido[2,3-d]pyrimidine-4,7(3H,8H)-dione, see PCT Publication No. WO2008/079814 published Jul. 3, 2008.